Bypassing the blowby gas system to a catch can?

[Will Ng]

The oil in the intake system, the constant vacuum on the rear main seal 
causing that nasty screeching noise, and that mushy oil-soaked rubber hose 
just waiting to burst, have me wanting to fab a catch can setup to route 
the blowby gases to it instead of back into the intake. I would probably 
vent to the atmosphere after the catch can. (don't tell the EPA)
And plug up the opening at the rubber air horn.
Besides removing the oily vapors that can cause detonation, it'll stop the 
rear seal problem. I'm probably running lean because of a vacuum leak 
there. I can hear occasional detonation when I accelerate even when the air 
temps are cool (60F). But the car idles fine at 700rpm.

Would removing the blow by from the intake cause running problems? My 
concern is whether the mixture ratio be altered since it'll be only fresh 
air passing through the intake.



Thanks,
Will
1990 200q @ 206k miles.